Method for the preburning preparation of fuels



Patented July 31, 1928.

UNITED STATES PATENT OFFICE.

JOSEPH MOSES WARD KITCHEN, OF EAST ORANGE, NEW JERSEY.

METHOD FOR THE PREBUBNING PREPARATION OF FUELS.

one-half of the coal that is mined becomes lost to the use of man, andthat the causes of such losses are various, and need removal. Among thelosses, is the fact that much the largest part of the crude coaldeposits produce smoke in their burning, are usually incompletely burnedso far as the gases evolved in their use is concerned, that some of themincluding so-called steaming coals, in their fracturing into gradedsized particles, roduce a large amount of small sized particlesincluding dust, that in high-volatile bituminous coals their volatileoily content is in such excess amounts that they swell, crumble and moreor less melt in their burning and compact the fuel-mass, and form slag,clinkers and funnels and hence pass excess air for combustion thru suchfuels when in fuel-masses. Above all other causes, is the fact of thewidespread ignorance of coal users as to the nature of combustionprocesses, and the need of economy in the use of fuels both for presentday and future uses of the world. As the result of such conditions, thepresent day does and the future day world will suifer'not only greatwaste of fuel and damage to health; but also, mining interests produceand accumulate large amounts of fuel-culm particles that are littleused, and when used, only sell for very low prices as compared with highcost graded anthracite, smokelessly burning coal.

What I propose as a remedy for this situation is practically possiblebecause of the fact that while anthracite coals only have from 3% to 7%of volatile content and do have a large ash-content, the soft coals contain from 20% to 40% ormore volatile content but lesser ash content, aremore easily mined and are hence produced at a lower cost per volume ofweight. Also, anthracite fines and'dust, and lignite coals can bepurchased at very low figures. But such. low cost materials in crudeform when burned in masses, become compacted and are so lacking inporosity that air for combustion does not easily find access into orthru such compacted materialsointo contact with the surfaces of the fuelarticles.

My inventive remedy for t' e latter situation is in part to so hardensoft coal by 5, 1926. SerialNo. 139,760.

its more or less coking that it will not swell, crumble and melt so asto effect compactive clogging of the fuel mass to gas passage as occursin the use of these crude soft coals; and then use the coked fuel togive porosity to fuel-masses that otherwise would be lackmg in poroustexture, the process being either thru admixture, or thru specialproduction of new forms of fuel.

I use for my purpose, cokes of various degrees ofhardening-carbonization as basic constituents in mixed fuel-masses, andin new solid fuels. lVith coke basic frameworks in fuel-masses, whichmay be replaced with hard particles of anthracite or graphitic coals, Iadmix enriching particles of uncoked coals richer in volatile content,such as bituminous slack or anthracite or semi-bitumlnous fines, invarying proportions that are in accord with the method I use in burningsuch fuels. In using induced natural draft in ordinary methods ofburning, only a smaller proportion of the enriching constituent is usedthan if a mechanically forced draft is used. In the latter case, alarger bulk proportion of soft coal or anthracite fines may be used.

As a special rule, I adniix relatively large sized graded particles ofcoke with smaller sized particles of enriching ingredients. I may havethe large sized coke or hard coal basic particles in juxtaposed contact,and only occupy a part of the intertices between the larger sizedparticles, with the smaller sized cnriching particles. This prevents thesmaller sized particles from becoming compactly compressed. In other.cases I completely fill, and more than fill the interstices withenriching small particles. I may enrich the coke by impregnation withlow cost heavy fuel-oils, and use such impregnated coke as a gas-formingand. enriching fuel. I may make thoroughly admixed mixtures of coke,high-volatile bituminous and anthracite dust, as a gas-forming fuel, andsubject such mixture, with or without fuel oil impregnation, to heat ina gas retort or on a traveling grate, and heat and drive ofi somevolatile matters from the admixture and melt the high-volatilebituminous constituent, which then incorporates with the anthracite dustand agglutinates with the coke, the agglutinated material being partlyabsorbed into the coke thru the capillary attractionof the coke. Ihismakes a. byproduct fuel, the heat of which. when IOU cooled by steam,forms water-gas, that may be admixed with other gases driven off fromthe mixed fuel in its heating, in a gas retort or on a traveling grate.

I make some mixtures that are of a character specially suitable forbanking fuels. For example: I admix moderate or small sized graded hard(anthracite or graphitic) coal particles, and crushed coke or cokedbreeze and anthracite dust in sufficient amounts and in correctproportions, to substantially fill all of the interstices between thehard coal particles, and thoroughly moisten the entire mixture. Thismakes an excellent banking fuel for various purposes, including therepression of the rates of combustion, in greenhouse boilers duringdaylight hours, and also for banking domestic furnace fires during nightsleeping hours.

I admix coke with fuel dust that ismoistened so as to prevent the flyingof dust and cinders in the burning of such mixtures,

either in the use of induced natural draft, or with mechanically forceddraft. In this case the moistened dust adheres to the rough coke poresand surfaces, and leaves the intercoals.

spaces more or less open. IVith forced draft, such mixtures in enormousquantities can be burned with advantage.

I admix large sized particlesof coke or hard coal with small sizedanthracite or medium or low-"olatile semi-bituminous soft By frequent orcontinuous feeding of such mixtures, large amounts of such fuels can beutilized thru the use of strong forced draft projected upwardly into themixtures, and thus securing great economy in the cost of fuels thru suchpractice. In such mixtures the smaller sized particles of coal burn morequickly than the larger sized particles, which larger sized particlesgravitate to the grate line before bccoming'entirely burned, and thereform a bed-shelf or platformresting on the grate, which intercepts andholds any unburned smaller sized particles until they are entirelyburned. This prevents grate sifting of the smaller sized particles.Large amounts of such low-cost fuel materials can thus be used.

Mixtures of coke or hard coal in large sized particles and in moderatebulk amounts and high-volatile connninuted or slacked bituminous coalsin larger bulk amounts, I

burn in heaps with or without forced draft; in which case, the heapsburn from their under surfaces, the gases and vapors escaping by ahorizontal travel thru the interstices between the large sized cokeparticles to the peripherv of the heaps, where more air rises thru thegrate and becomes admixed with and burns with the unburned volatilizedmatters, and at which peripheral oint, other air can be forced intoquick and intimate contact with the vapors and gases in the combustionspace. The heat of complete combustion produced at such pomts, isusually in close contact with the heating surfaces, and is thereabsorbed progressively in the gravitational rise of the burned gasesagainst the heating surfaces.

In my copending applications Ser. Nos. 703,006; 706,201; 710,426;717,197; new Ser. Nos. 67 ,182 and 239,964, I describe and illustratehow I admix air with burnable gases in connection with various forms ofstationary and moving'grate's, and secure substantiallyeonipletecombustion of my preburning prepared low cost or other fuels.

In the mixtures I use, I secure thru uniformity of texture a greateruniformit of rates of combustion in all parts of the fuelbed, and thusavoid the losses due to the passage of excess air of combustion thru thefuel-bed,and due to unequal combustion in various parts of the fuel-bed.

'Thoroughncss of admixture of the constituents of my fuel mixtures is ofgreat importance, and on that account I preferably use mechanicallyrotating mixers to secure such uniformity of texture in fuel-masses.This uniformity of texture prevents the formation of air-passingfunnels, and also. formation of masses of slag in the fuel-bed. 1 In mycopending application Ser. No. 697,769, I describe and illustrate how Iconvert admixed fuels, including coke impregnated with heavy fuel-oils,into low cost fuelgases of various thermic values. and incidentallyproduceas a byproduct, the low costsmokelcss solid fuel claimed in thepresent application. In that process heat developed in the process isconverted into water gas. The same solid fuel can be produced ontraveling grates as a byproduct in generating steam for process or poweruses. the b vproduct fuel being used in cycle with repeated enrichingadmixtures with high-rob atile bituminous fuels. 7

In my copending applications Ser. Nos. 703,000; 706,201; 710,496;717,197 and 67. 182, I disclose and claim special methods of burningmyfuel mixtures under mechanically controlled draft by introducing air forcombustion into and over fuel-masses in specially desired amounts atspecially selected points of air introduction. Such methods are a partof the present invention.

In the copending application Ser. No.

697,769, I describe preferred methods of producing various fuel productsin one special apparatus, in which gases of various chara ters as wellassolid fuelsare economicallv produced, and in which the heat of theprodess is utilized regeneratively in producing water gas, as well as incleaning gases. In the present case, "my claims are restricted toproducing the special fuel roducts herein described as s ecific fuels,al of which have special value or special purposes.

The degrees of heat I apply to soft coals in their hardening will varyaccording to the nature of the coke product wanted. High temperaturecoke is of special value for impregnation with fuel oils. Lowtemperaturecarbonized coke is good to use in mixtures for generating producer orother gases if impregnated with fuel oil; or, after crushing, foradmixture with other solid fuel materials. So long as the porosity of afuel-mass is attained and maintained to secure a sufficient heatingeffect, the more volatile enriching matter added to the hardened fuel,the better.

What I claim as new, is:

1. The method which consists in mixing coke of relatively large sizedparticles, highvolatile bituminous coal particles of relatively smallersize, and anthracite dust, subjecting the mixture to abituminous-coalmelting temperature, and cooling the product of theprocess.

2. A new fuel which consists of coke particles having agglutinativelyadherent to the coke particles, agglutinated high-volatile soft coal andhard coal dust.

3. The method which consists in producing a liquefied form ofhigh-volatile soft coal. securing the agglutinated absorption by andadherence of the liquefied coal with coked particles of coal, theprocess including a preliminary melting-heating of the soft coal and itssubse uent cooling and hardening.

4. A new fuel composed of particles of hard coke, coated with adherentsoft coal that has been liquefied by heating and subsequently cooled.

5. The method which consists in heating and coking a mixture of largesized particles of coked coal and small sized particles of high-volatilesoft coal and producing a volatilized burnable gas from a part of thevolatile content of the mixture and a liquefied adherence of a part ofthe high-volatile constituent of the mixture to the coked coal.

6. A new fuel byproduct secured by admixing particles of coke and softcoal, subjectin the admixture to a meltin and volati e-volatilizing heatand gasifymg a agglutinated coke and unutilized aggluti-.

nated soft'coal.

7. The method which consists in liquefying a soft coal and securing theabsorptive adhesion of the liquefied soft coal with particles of coke.

8. The method which consists in coking soft coal sufficiently to hardenthe coal, admixing the coked coal with comminuted particles of soft coaland other enriching coal product material, bringing the admixture to aliquefying temperature and agglutinating the liquefied material and thesufiiciently hardened coal, and hardening the agglutinating material bycooling.

9. A fuel composed of coke agglutinated with hardened melted coalmaterials containing highvolatile soft coal.

10. A fuel com osed of coke impregnated with cooled lique ed soft coal.

11. A particle of coke having agglutinated with the coke, dry adherentsoft coal.

12. A fuel-mass composed of admixed particles of coke and comminutedsmall particles of semi-bituminous lowvolatile coal.

13. The method which consists in mixin coke particles of relativelylarge size, so coal particles of comminuted or slacked sizes smallerthan the coke particles and fuel oil, subjecting the mixture to asoft-coalmelting heat until the soft coal melts and becomesagglutinatively adherent with the coke particles.

14. The method which, consists in mixing particles of high-temperaturecoke of relatively large size and particles of soft coal moistened witha petroleum oil fractionate, subjecting the mixture to a soft coalmelting and volatile-volatilizing heat and volatilizing and gasifyingpart of the mixture and agglutinatin the balance of the coal intoadherence with the coke particles, and cool ingl'l with steam theagglutinated coke and soft co JOSEPH MOSES WARD KITCHEN. I

